More than 10 million cancer survivors are alive in the US today, and there is a need to promote the health and well being of these individuals. Prolonging the survival of cancer patients, including preventing a second primary cancer and other chronic diseases such as cardiovascular disease, is one important goal. Epidemiologic studies have shown that physical activity can prevent the development of several cancers. Additionally, in studies of the general population (not focusing on cancer survivors), physical activity also has been shown to decrease the rates of cardiovascular disease, the leading cause of death in the US, and to delay mortality. It would thus seem reasonable to assume that physical activity in cancer patients favorably affects survival. While several studies have shown that physical activity is associated with better quality of life in cancer survivors, there are almost no data regarding whether physical activity improves survival among these individuals. To provide information, we propose to take advantage of the Harvard Alumni Health Study, an ongoing cohort study, to examine whether physical activity in men with cancer can improve survival. In 1988, 1,683 men (mean age, 67 years) with physician-diagnosed cancer (diagnosed a median of 7 years ago), returned a health questionnaire with detailed information on physical activity, as well as other health habits and medical history. On the questionnaire, they provided consent to contact their physicians. We are seeking funds to ascertain information on cancer stage and treatment from alumni physicians. Between 1988 and 1998 (the last year of follow-up available), 566 men died;297 from cancer. We also seek funds to ascertain additional deaths that occurred among these men after 1998 to the present. We will obtain death certificates and ascertain cause of death. We will then examine whether physical activity predicts overall survival and survival from cancer mortality among these men. We will further examine the amount and kinds of physical activity needed to improve survival. With the additional decedents that we will identify under this application, we estimate that we will have sufficient power for the hypotheses of interest. This study will add important information because of the large number of cancer survivors in the US. It will help clarify whether physical activity, an inexpensive, modifiable behavior with little adverse effect, can prolong survival in cancer patients.